This paper presents a complete Bayesian methodology for analyzing spatial d
ata, one which employs proper priors and features diagnostic methods in the
Bayesian spatial setting. The spatial covariance structure is modeled usin
g a rich class of covariance functions for Gaussian random fields. A genera
l class of priors for trend, scale, and structural covariance parameters is
considered. In particular, we obtain analytic results that allow easy comp
utation of the predictive distribution for an arbitrary prior on the parame
ters of the covariance function using importance sampling. The computations
, as well as model diagnostics and sensitivity analysis, are illustrated wi
th a set of precipitation data.